Conventionally, there has been provided a hot-water storage type heating and hot-water supply device which includes a heat pump unit for heating water, and a hot-water storage tank for storing hot water heated by the heat pump unit, so that heating or hot water supply is fulfilled by utilizing hot water contained in the hot-water storage tank (see, e.g., JP 2006-329581 A).
In this hot-water storage type heating and hot-water supply device, hot water stored in the hot-water storage tank is outputted as it is. By contrast, in some other cases, a hot-water supplying heat exchanger is placed in the hot-water storage tank in terms of sanitation or the like, and hot water is outputted from a water supply port via the hot-water supplying heat exchanger. In a hot-water storage type heating and hot-water supply device with use of such a hot-water supplying heat exchanger, there is a problem that it is quite difficult to realize a hot-water supplying heat exchanger capable of performing efficient heat exchange between the hot water in the hot-water storage tank and the supply hot water.